STOCK BASED COMPENSATION Compensation costs related to the stock-based compensations plans (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life	10 years
Number of shares available for future grant	1,900,000
Share limit, current year (in shares)	1.5
Unrecognized stock-based compensation expense	$ 6,000,000
In-the-money stock options exercisable	$ 3.60	$ 3.04	$ 2.44
Total stock-based compensation expense	6,075,000	4,396,000	4,442,000
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	823,000	617,000	567,000
Engineering, research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,248,000	1,616,000	1,530,000
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,004,000	$ 2,163,000	$ 2,345,000
Stock Options And Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated forfeiture rate	4.20%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period over which the unearned stock-based compensation is expected to be recognized	1 year 2 months 12 days
Outstanding restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period over which the unearned stock-based compensation is expected to be recognized	1 year 7 months 6 days